Clever Calculators

Roman Numeral Converter

Convert numbers to Roman numerals and Roman numerals back to numbers, from 1 to 3,999.

Result
Result

Enter a number from 1 to 3,999, or a Roman numeral.

Type a number (1–3,999) to get its Roman numeral, or type a Roman numeral to convert it back to a number. It detects which direction you need automatically.

Frequently asked questions

Why do Roman numerals stop at 3,999?

Standard Roman numerals only go up to 3,999 (MMMCMXCIX). Larger numbers historically used a bar over symbols to multiply by 1,000, but that isn't part of the common notation.

How does subtractive notation work?

When a smaller numeral appears before a larger one, it's subtracted. So IV is 5 − 1 = 4, IX is 10 − 1 = 9, and XL is 50 − 10 = 40.